The following includes information that may be useful in understanding the present invention(s). It is not an admission that any of the information provided herein is prior art, or material, to the presently described or claimed inventions, or that any publication or document that is specifically or implicitly referenced is prior art.
1. Field of the Invention
The present invention relates generally to the field of ladder anti-slip devices and more specifically relates to a rapid installation and removal ladder slide prevention system.
2. Description of the Related Art
A ladder is a vertical or inclined set of rungs or steps. The most common types of ladders are rigid and can be leaned against a vertical surface such as a wall. The vertical members of a rigid ladder are called stringers or rails or stiles. Rigid ladders are usually portable, but some types are permanently fixed to buildings. They are commonly made of metal, wood, or fiberglass, but they have been known to be made of tough plastic. Portable industrial ladders are made of fiberglass for electrical arc prevention. Nearly all ladders manufactured for sale today have some sort of feet attached for added stability. The feet often swivel so that the bottoms of the feet can be placed flat against the floor or ground surface to provide greater ground contact surface area. Rubber grips on the bottoms of the ladder feet are designed to add a degree of grip so that the bottoms of the feet do not slide away from the vertical surface the ladder is leaned against. Often though, the ladder feet can still slip and move on certain types of surfaces. When the rubber grips become hardened, they tend to cause sliding rather than preventing it. This is not desirable.
Fatalities are added to statistics annually because of falls from ladders. The most common injury made by ladder climbers is bruising from falling off the ladder, and so for safety, a rigid ladder should be leaned at an angle of about fifteen degrees to the vertical. In other words, the distance from the foot of the ladder to the wall should be about one quarter of the height of the top of the ladder. At steeper angles, the ladder is at risk of toppling backwards when the climber leans away from it. At shallower angles, the ladder may lose its grip on the ground. The correct angle is difficult for inexperienced users to judge. Even experienced users make the mistake of placing the bottom of the ladder on incompatible gripping surfaces. On softer ground surfaces, even ladder feet in good condition can be unstable because of uneven or soft ground. Harder surfaces tend to promote sliding rather than maintaining a grip.
Different methods have been used to stabilize ladders, many with permanent attachments. Federal statutes regulate methods that involve permanent attachments to ladders. Drilling holes in a ladder to install add-on equipment that is not made for or designed by the ladder manufacturer for a particular ladder is generally unacceptable due to possible weakening of the ladder rails. A registered engineer must provide documentation specifying that modification designs and installation method are safe, which makes most methods illegal in industrial environments. Ladders are rarely, if ever, manufactured with non-slip equipment beyond the feet rubber grips. A quickly installable non-slip system that does not alter the structure of the ladder is needed in the interest of worker safety.
Various attempts have been made to solve the above-mentioned problems such as those found in U.S. Pat. Nos. 6,935,463; D343907; 4,836,331; 1,346,831; 2,127,035; and 5,865,268. This art is representative of ladder anti-slip devices. None of the above inventions and patents, taken either singly or in combination, is seen to describe the invention as claimed.
Ideally, a ladder anti-slip device should provide ease of installation and removal and, yet would operate reliably and be manufactured at a modest expense. Thus, a need exists for a reliable rapid installation and removal ladder slide prevention system to rapidly install and remove a ladder slip prevention device to promote safety and to avoid the above-mentioned problems.